U.S. National Archives & Records Administration (NARA), record group 104 (U.S. Mint), entry 1 (General Correspondence, 1792-1857), boxes 41 to 45, scanner images 2001 to 2397. Scanned under the direction of Robert W. Julian at the NARA Philadelphia facility, operating via a grant from the Central States Numismatic Society. Note, for correspondence, endorsements were generally not copied. Boxes 41 to 45 cover the period June 1855 to February 1857.